(Think maybe some paternal instinct will kick in and he'll feel like he can play a part in her "upbringing"? )

Funny that you mention it, because just today I was thinking about their respective ages (that part of the chapter with him was written quite some time ago, so it's not so fresh to me) and I wondered if Zamarran isn't old enough to be her father. He isn't, but with her young look (she appears young to them due to lack of ridges) and "childish" behaviour he would have some paternal instincts kicking in

And yes, I think that a lot of their social behaviour is an instinct. I think the instinct came first and culture later, as it grew "over" that instinct.